1. Field of the Invention
This invention constitutes a means and method for the treatment of arterial stenoses by the use of an Expandable Transluminal Atherectomy Catheter (ETAC) system.
2. Description of the Prior Art
Arterial stenoses are becoming increasingly common as life expectancy increases. There are numerous treatments to open stenotic lesions including surgical interventions such as endarterectomy and by-pass surgery using veins or artificial graft materials. Ballon angioplasty is becoming increasingly popular for the dilation of arterial stenoses. More recently atherectomy, the excision from the body of atheromatous plaque, has been successfully used to open arterial stenoses. U.S. patent application Ser. No. 874140 filed by R. E. Fischell and T. A. Fischell on June 13, 1986 entitled "A Guide Wire Following Tunneling Catheter System for Transluminal Arterial Atherectomy" first described a forward motion (anterograde) cutting, single lumen atherectomy catheter that is advanced over a guide wire. A disadvantage of that and other anterograde cutting atherectomy devices is that they can only cut a hole in the stenosis as large as their own fixed diameter. This is a distinct disadvantage in that it is generally preferable to percutaneously enter the femoral artery at the groin with a catheter no larger than 3.0 mm in diameter, and then to excise plaque close to the arterial wall for arteries that are larger in diameter than 3.0 mm. For example it would be desirable to remove plaque to the diameter of the unoccluded arterial lumen for a 4 mm diameter coronary artery, a 5 mm diameter femoral or renal artery and a 5 to 7 mm diameter internal or common carotid artery. Although U.S. Pat. No. 4,765,332, issued Aug. 23, 1988 to R. E. Fischell and T. A. Fischell entitled "Pullback Atherectomy Catheter System" describes an effective retrograde atherectomy catheter system, it also does not teach a method for entering the artery with a 3 mm diameter catheter and removing plaque to larger diameters. U.S. patent application Ser. No. 153,912 filed Feb. 9, 1988 by R. E. Fischell and T. A. fischell entitled "Expandable Pullback Atherectomy Catheter" did however show a method for excising plaque by a cutting means that could expand at its distal end to a larger diameter than the basic diameter of the catheter body after insertion into the artery. However, the retrograde cutting device must first pass through the stenosis before expanding which could be disadvantage, particularly for treating a severely narrowed artery.
U.S. Pat. No. 4,631,052 by K. R. Kensey entitled "Method and Apparatus for Surgically Removing Remote Deposits" describes a means for distally occluding the artery just beyond the stenosis to prevent the distal arterial embolization of particulate debris that might be released during the atherectomy procedure. However, Kensey's invention does not teach the unique occlusive balloon inflation means suggested herein which uses a hollow guide wire to provide fluid communication between the balloon and a source of fluid that lies outside the body.